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I have searched the best I could before posting this. All I pretty much found were threads about not using synthetic fluids in OEM t56s. I bought this kit for rebuilding my tranny. Now, will I be able to with this or still recommended not to?
I have searched the best I could before posting this. All I pretty much found were threads about not using synthetic fluids in OEM t56s. I bought this kit for rebuilding my tranny. Now, will I be able to with this or still recommended not to?
It's a serious job for an advanced DIY. The first problem is removing the rear drive unit, the transmission, and torque tube in a manner that will not damage any of those components.
After that, there likely are some rather expensive special tools necessary to disassemble and rebuilt the T56.
If you insist on doing the work yourself, I highly recommend the Factory Service Manual or a subscription to GM online service information. Also, since transmission overhaul is not covered by the FSM or GMSI, you're going to need a copy of another GM service publication, the "Unit Repair Manual" for your model year.
As for not using synthetic fluids in "OEM t56s"...I've owned a 2004 ZO6 for 18 years and about 50,000K mi. I have used Red Line Synthetic Superlight Shockproof Gear Oil in it the whole time. The advantages of SLSP are much better thermal stability, far better lubrication under severe duty and lower shift effort.
I suggest, unless you are an advanced DIY with a lot of standard hand tools, as well as, some GM special tools, that you return the kit for a refund and go looking for a reman transmission and a service facility to install it.
It's a serious job for an advanced DIY. The first problem is removing the rear drive unit, the transmission, and torque tube in a manner that will not damage any of those components.
After that, there likely are some rather expensive special tools necessary to disassemble and rebuilt the T56.
If you insist on doing the work yourself, I highly recommend the Factory Service Manual or a subscription to GM online service information. Also, since transmission overhaul is not covered by the FSM or GMSI, you're going to need a copy of another GM service publication, the "Unit Repair Manual" for your model year.
As for not using synthetic fluids in "OEM t56s"...I've owned a 2004 ZO6 for 18 years and about 50,000K mi. I have used Red Line Synthetic Superlight Shockproof Gear Oil in it the whole time. The advantages of SLSP are much better thermal stability, far better lubrication under severe duty and lower shift effort.
I suggest, unless you are an advanced DIY with a lot of standard hand tools, as well as, some GM special tools, that you return the kit for a refund and go looking for a reman transmission and a service facility to install it.
I work at a GM dealership. I am not a service tech yet, but learning the process to one day become one (gotta learn it one day). My co-worker will be teaching me how to repair the mm6 and guide me through it, let alone replacing the clutch, rebuilding the torque tube, etc. I have looked at the GM Service Information (mostly geared towards 4l60, even then nothing about overhauling it), and it doesn't have anything on their about repairing.
Originally Posted by Hib Halverson
As for not using synthetic fluids in "OEM t56s"...I've owned a 2004 ZO6 for 18 years and about 50,000K mi. I have used Red Line Synthetic Superlight Shockproof Gear Oil in it the whole time. The advantages of SLSP are much better thermal stability, far better lubrication under severe duty and lower shift effort.
Apparently my mm6 had paper blocker rings which didn't like synthetic fluid. I know RPM recommended using Royal Purple for their rebuilds. On the other hand, people even have said don't even use synthetic as all. Since buying the rebuild kit above, just wanted to see if I could use synthetic.
I just did the trans Fluid dump and refill on my 98',
Everyone has their favorites. I just went with the factory fill after reading about the paper blocker rings on the pre-2001 trans. I also added magnetic drain plugs for all the fluids, I have to tell you the original 1998 M6 trans fluid I removed was not as red as it should have been at 44k. Nasty dirty. Hard to believe they say this a 100k lubricant in the owners manual.
YMMV.
I just did the trans Fluid dump and refill on my 98',
Everyone has their favorites. I just went with the factory fill after reading about the paper blocker rings on the pre-2001 trans. I also added magnetic drain plugs for all the fluids, I have to tell you the original 1998 M6 trans fluid I removed was not as red as it should have been at 44k. Nasty dirty. Hard to believe they say this a 100k lubricant in the owners manual.
YMMV.
I second factory fill. I have 92k miles on my car and just had the dealer replace all of the fluids - this being one,
Yes to synthetic after a rebuild. I don't think paper blocker rings have been available for a long time.
It makes you wonder why the Hell Borg Warner, or Tremec, ever used them to start with. My guess is poor engineering, inept beancounters, or BOTH. I'll be first to admit the Japanese and Korean Mfrs have forced American companies to build better cars. But it seems to me, as an older guy, that cars engineered in the 1950s-1960s had far less trouble with drivetrain issues, like differentials burning up with no seviceable parts inside, weak transmissions, etc. Seems like we have become the guinea pigs for big corporations. It used to be design and build. Now,its more like build, then redesign!!! I digress.......
Last edited by grinder11; May 22, 2022 at 02:19 PM.
I work at a GM dealership. I am not a service tech yet, but learning the process to one day become one (gotta learn it one day). My co-worker will be teaching me how to repair the mm6 and guide me through it, let alone replacing the clutch, rebuilding the torque tube, etc. I have looked at the GM Service Information (mostly geared towards 4l60, even then nothing about overhauling it), and it doesn't have anything on their about repairing.
See if your employer has a copy of the "Unit Repair Manual" for your model year. That's where you will find trans rebuilding service info.
Apparently my mm6 had paper blocker rings which didn't like synthetic fluid. I know RPM recommended using Royal Purple for their rebuilds. On the other hand, people even have said don't even use synthetic as all. Since buying the rebuild kit above, just wanted to see if I could use synthetic.
It is true that early T56es had "paper" blocker rings. It's a little hard to find concise information on that, but I believe the 1997-1999 T56s had the paper rings.
If you are going to overhaul the trans the solution is: use the later CF blocker rings.
Transmission fluid
